This invention relates to an antidandruff shampoo containing a low pH surfactant system and Climbazole which provides increased deposition of Climbazole on the skin and enhanced antidandruff efficacy. This increased antidandruff efficacy is believed to be the result of increased deposition of Climbazole to the skin at a reduced pH of about 4-5.
The prior art discloses the imidazolyl ketones such as 1-imidazolyl-1-(4-chlorophenoxy)-3,3-dimethylbutan-2-one, in U.S. Pat. Nos. 3,812,142 and 3,903,287 as antimycotic agents, useful in pharmaceutical compositions including aqueous suspensions containing surface active agents such as polyoxyethylene sorbitan fatty acid esters. British Pat. No. 1,502,144 and its German counterpart, Pat. No. 2,430,039, disclose cosmetic compositions such as shampoos containing the imidazolyl ketone antimycotic agents dispersed in a dermatologically acceptable carrier in the form of creams, aerosols, powders and liquids. Although the shampoo formulas disclosed on pages 35-36 of the British patent do not specify pH, a dermatologically acceptable carrier would have a pH of about 5.5-6.5 (skin pH). This is substantiated by the disclosure on page 27 in which a test of the shampoo against Pityrosporum is conducted at pH 6.4.
Also disclosed in the prior art are surfactant based antimicrobial shampoos containing Climbazole and having a pH of 6.5 to 7.5, as shown in U.S. Pat. Nos. 4,329,334; 4,329,335; and 4,329,336.
U.S. Pat. No. 4,457,938 discloses a stick formulation containing 0.05-1.0% of an antimycotic azole derivative such as Climbazole.
U.S. Pat. No. 3,658,985 discloses a liquid shampoo containing an aqueous detergent composition, an oil and a fluorescent dye adjusted to a pH relatively close to neutral, preferably a pH of 6.5-8.5. No Climbazole ingredient is disclosed therein.
Shampoos having acidic pH of 3 to 4.5 are disclosed in U.S. Pat. No. 4,321,156, having a pH of 2 to 4 in U.S. Pat. No. 4,636,392, having a pH of 5 to 7.5 in European patent application No. 0,160,269, and having a pH of 5 to 7 in British Pat. No. 2,161,172A. All of the aforesaid shampoos are mild conditioning shampoos containing various combinations of surfactants. No antidandruff agent is disclosed in these shampoo compositions.
European patent application No. 0202621 discloses a clear therapeutic hair care composition having a pH of 3 to 6.5 and preferably 4.9 to 5.7 containing a detergent shampoo base, a keratolytic agent such as a salicylate, and a stabilizing agent such as tertiary amines, ascorbic acid and sodium sulfite, to stabilize said salicylate against oxidative decoloration decomposition.
However, there is no disclosure of an antidandruff liquid shampoo comprising a low pH of about 4 to 5, and a surfactant system containing about 0.10 to 2.00% by weight of the imidazolyl ketone antidandruff agent, namely Climbazole, and a water soluble surfactant system comprising an anionic surfactant and a minor amount of either a nonionic, cationic or amphoteric surfactant or a mixture thereof.